A system designed to incorporate FIMS permits handling of semiconductor wafers inside and outside of clean room facilities by interfacing a clean semiconductor wafer cassette transport box or pod to a clean environmental housing for semiconductor processing equipment or to other clean environments. The system concept entails mating a box door on a front-opening unified pod (FOUP) or cassette container box to a port door on an equipment enclosure and transferring the cassette into and out of the processing equipment without exposing to outside contamination the semiconductor wafers carried by the pod or wafer cassette.
A standard interface is required for cassette transport boxes intended to control the transport environment of cassettes containing semiconductor wafers. The standard interface addresses the proper transport box orientation for material transfer and maintains continuity between the transport box and semiconductor processing equipment environment to control particulate matter. The FIMS specifications are set out in the Semiconductor Equipment and Materials International (SEMI) standard SEMI E47-, E57-, E62-, and E63-0298 (1996–1998).
A FIMS system includes minimum volume, sealed front-opening boxes used for storing and transporting semiconductor wafer cassettes and canopies placed over wafer processing areas of semiconductor processing equipment so that the environments inside the boxes and canopies in cooperation with clean air sources become miniature clean spaces. The boxes are made of plastic materials having registration features located relative to one another within and of sizes characterized by relatively wide tolerances that can affect equipment alignment precision. What is needed is a box load interface implemented as part of a transfer mechanism for precise box alignment during loading and unloading of wafer cassettes from a sealed box without external environment contamination of the wafers carried by the wafer cassette.